is dug into the contaminated soil, which serves as the melting container. Very large electrodes are positioned within the cavern to optimize melting times. The hazardous waste is then mixed with soil inside the cavern and the melt is initiated. After the glass product has been formed, it is either left in the ground or transferred to a disposal facility. Advantages SPV melts do not require much capital investment, because the only construction necessary is the cavern that must be dug and the retrieval of the vitrified mass after the melt. SPV melts cost roughly $355–461 per ton of processed waste. When compared to the disposal cost of $555 per kilogram (or $500,000 per ton) of nuclear waste, SPV is very cost-effective. There is also very little risk of worker injury on the job because the melting process happens underground and away from the workers at the site. Finally, the melt caverns have no size restrictions, so SPV can handle very large volumes of waste at once. Disadvantages SPV does not come without its drawbacks. In order to perform an SPV melt, all materials and personnel must be moved to the melting site, so the costs of transportation for both must be taken into consideration. Once all contaminants have been removed or destroyed at the site, the project must relocate to continue operations. Melts cannot begin immediately after a treatment team arrives because it takes a few hours to dig the caverns and position the electrodes inside. In-Container Vitrification (ICV) In-container vitrification melts are carried out above ground in a container made of heat-resistant metal coated with a protective layer of sand. The sand separates the container walls from the molten mixture and shapes the glass product after it has cooled. Melts are carried out in quick succession; once one melt has cooled, another waste container is loaded with electrodes and the process begins again. The vitrified glass is then sent to a disposal facility. Advantages Because these melts are carried out at a treatment facility, all melts are efficient and centralized to that location. Waste/soil mixtures are systematically loaded and processed in the facility. Since the mixtures are melted above ground, machines do not have to dig up the glass product like in SPV melts. The melt containers are also the containers used to transport the glass, so there are fewer transfers involved in the glass's disposal. Disadvantages ICV